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Re: [Qemu-devel] [PATCH] slirp: fix clearing ifq_so from pending packets
From: |
Thomas Huth |
Subject: |
Re: [Qemu-devel] [PATCH] slirp: fix clearing ifq_so from pending packets |
Date: |
Wed, 30 Aug 2017 09:50:45 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 |
Hi Samuel,
On 26.08.2017 00:37, Samuel Thibault wrote:
> The if_fastq and if_batchq contain not only packets, but queues of packets
> for the same socket. When sofree frees a socket, it thus has to clear ifq_so
> from all the packets from the queues, not only the first.
I think you should CC: this to qemu-stable if it's fixing a problem that
can be used by the guest to crash QEMU... ?
Thomas
> Signed-off-by: Samuel Thibault <address@hidden>
> Acked-by: Philippe Mathieu-Daudé <address@hidden>
> ---
> slirp/socket.c | 39 +++++++++++++++++++++++----------------
> 1 file changed, 23 insertions(+), 16 deletions(-)
>
> diff --git a/slirp/socket.c b/slirp/socket.c
> index ecec0295a9..cb7b5b608d 100644
> --- a/slirp/socket.c
> +++ b/slirp/socket.c
> @@ -59,6 +59,27 @@ socreate(Slirp *slirp)
> return(so);
> }
>
> +/*
> + * Remove references to so from the given message queue.
> + */
> +static void
> +soqfree(struct socket *so, struct quehead *qh)
> +{
> + struct mbuf *ifq;
> +
> + for (ifq = (struct mbuf *) qh->qh_link;
> + (struct quehead *) ifq != qh;
> + ifq = ifq->ifq_next) {
> + if (ifq->ifq_so == so) {
> + struct mbuf *ifm;
> + ifq->ifq_so = NULL;
> + for (ifm = ifq->ifs_next; ifm != ifq; ifm = ifm->ifs_next) {
> + ifm->ifq_so = NULL;
> + }
> + }
> + }
> +}
> +
> /*
> * remque and free a socket, clobber cache
> */
> @@ -66,23 +87,9 @@ void
> sofree(struct socket *so)
> {
> Slirp *slirp = so->slirp;
> - struct mbuf *ifm;
>
> - for (ifm = (struct mbuf *) slirp->if_fastq.qh_link;
> - (struct quehead *) ifm != &slirp->if_fastq;
> - ifm = ifm->ifq_next) {
> - if (ifm->ifq_so == so) {
> - ifm->ifq_so = NULL;
> - }
> - }
> -
> - for (ifm = (struct mbuf *) slirp->if_batchq.qh_link;
> - (struct quehead *) ifm != &slirp->if_batchq;
> - ifm = ifm->ifq_next) {
> - if (ifm->ifq_so == so) {
> - ifm->ifq_so = NULL;
> - }
> - }
> + soqfree(so, &slirp->if_fastq);
> + soqfree(so, &slirp->if_batchq);
>
> if (so->so_emu==EMU_RSH && so->extra) {
> sofree(so->extra);
>